Metallic ladder



R. PIBEGGS 2,183,251 METALLIC LADDER Dec. 12, 1939;

Filed Jan. 23, .1939

Patented Dec. 12, 1939 UNITED STATBS METALLIG LADDER Ray P. Beggs,Oklahoma City,'0kla., assignor to George W. Hassell, Oklahoma City,Okla.

Application January 23, 1939, Serial No. 252,460

3 Claims.

This invention relates to foldable metallic ladders. The development ofthe airplane has brought upon the market, and made available for use,tubing which, while being very light, is also exceedingly strong. It isthe primary object of the present invention to use this tubular materialin connection with the construction of foldable metallic ladders, and toemploy in conjunction therewith a novel means for rendering the hingedjoints between the ladder sections very strong and rigid when the ladderis extended for use.

In the accompanying drawing:

Figure 1 is a fragmentary side elevation of a portion of the laddershowing the manner in which a number of sections may be hinged togetherin such fashion that they may be folded into very small compass when notin use;

Fig. 2 is a front elevation of a portion of the ladder showing one ofthe joints hereinafter described;

Fig. 3 is a fragmentary vertical section upon line 3-3 of Fig. 2;

Fig. 4 is a detail view of a brace plug, hereinafter described, and

Fig. 5 is a horizontal sectional view upon line 55 of Fig. 3.

Like numerals designate corresponding parts throughout the severalfigures of the drawing.

In the drawing, A, B and C represent ladder sections hingedly connectedto each other, as indicated at 5, to adapt them to be folded in thedirections indicated by the arrows. The several sections consist of siderails 6 and cross rungs l. The sections 6 consist of tubes, and therungs 1 may consist of rods or tubes, welded into place between therails 6 to constitute steps in the manner common in ladders.

The elements 6 and 1 may be made of any of the well known, light, andexceedingly strong alloys which have recently found such wide favor inthose places where great strength coupled with light weight isessential. Duralumin, for example, is a material which I may employ inthe manufacture of these ladders.

Plugs 8, which may be either solid or of tubular formation, are slidablydisposed within the tubular rails and in a position to span the jointsbetween the meeting ends of the rails. These plugs are made to fit sosnugly that while they may be easily slid into overlapping relation withrespect to the joints, they prevent any wobbling at the joints.

A slidable rung l associated with each of the meeting ends of a pair ofsections, serves the double function of a rung and of an actuating meansfor the associated plugs 8. This slidable rung has its end engaged inthe transverse slots 8 of the respective plugs, and said slidable rungtravels in slots 9, of inverted J-shape, formed in the inner faces ofthe rails 6 of the section B, for example.

When it is desired to collapse the ladder, the slidable rung is moveddownwardly in the slot 9 until said rung lies adjacent the next lowerfixed rung, indicated at l in Fig. 3. This lowering of the slidable runglowers the plugs 8 until said plugs no longer overlap the joint, or, inother words, no longer project upinto the next uppermost ladder sectionA. The ladder sections may then be folded together as described.

When it is desired to extend the ladder sections for use, they are swunginto alignment with each other, and the slidable rungs are movedupwardly in slots 9 to bring the plugs 8 to the position illustrated inFig. 3, at which time said plugs overlap the joint and lie partly in thesection A and partly in the section B. This rigidly aligns the laddersections and prevents any wobbling at the joint.

To hold the plugs in the elevated position described, the slidable rungis slipped laterally in the slots 8 of the plugs to lie in thedownwardly curved portion 9 of said slots. Thus, it requires a-positiveupward and then a lateral movement of the rung to bring said rung intoposition to descend and move the plugs to ladder section releasingposition. Consequently, there is no possibility of an accidentaldisengagement of the plugs, with possible consequent injury to theperson using the ladder.

While the construction shown and described is an exceedingly simple,strong and economical one, it will be apparent that other ways may beresorted to for accomplishing the same general result. Consequently, itis to be understood that the invention is not limited to the particularmeans shown and described for actuating theplugs or for supporting themin elevated position. Upon the contrary, the invention includes withinits purview any equivalent way of accomplishing this result fallingwithin either the terms or the spirit of the appended claims.

Having described my invention, what I claim is:

1. In combination, hinged ladder sections comprising tubular, metallicrails and metallic rungs, means for hingedly connecting the abuttingrails of adjacent ladder sections, members slidably mounted within thetubular rails and movable to and from overlapping position with respectto the joint between the said rails, and means for holding said membersin such overlapping position, said last-named means comprising aslidable rung engaged with said members and means for supporting saidrung in position to hold said members in joint-overlapping position asdescribed.

2. The combination with a pair of tubular ladder sections, eachcomprising a pair of tubular side rails and integral metallic rails, therails of one ladder section being provided with slots upon its innerface, of a pair of plugs slidably mounted in the side rails of oneladder section and adapted to be projected into overlapping engagementwith the side rails of the next adjacent section, and means movable insaid slots for actuating said plugs, the means movable in the slotscomprising a transverse bar constituting a slidable rung.

3. The combination with a pair of ladder sections, each comprising apair of tubular metallic side rails and a plurality of transverse,integral rungs, of means for hingedly connecting the meeting ends of theside rails of one ladder section with the ends of the side rails of anadjacent ladder section, the side rails of one section being providedupon their inner faces adjacent their hinged ends with vertical slots,said slots being curved over at their upper ends to form offsetrecesses, plugs slidably mounted in the side rails for movement tooverlapping position with respect to the joint between the rails of theadjacent sections, a slidable rung vertically movable in said slots, andmeans for connecting the ends of said rung to the plugs in such manneras to permit lateral movement of the rung with respect to the plugs,such lateral movement permitting the lateral shifting of the rung withrespect to the plugs to cause said rung to lie in the off-set recessesof the slots and to thereby hold the plugs in elevated position and inoverlapping relation to the joints between the ladder sections, as andfor the purposes described.

RAY P. BEGGS.

